Power transmission



Dec. 24, 1940. H. F. PATTERSON ETAL 2,226,014

POWER TRANSMISSION Filed Nov. 26, 1937 5 Sheets-Sheet l INVENTORS IYERBER'Iv F. PATTERSON BY HUGU6 //v d. 5YROVY- 4M 1 ATTORNEY 1940- H. F. PATTERSON ETAL 2,226,014

POWER TRANSMI S S ION 5 Sheets-Sheet 2 Filed NOV. 26, 1937 INVENTORS Y Y m M Tm m TY M6 WA d? N v TWMM W 5m HM 1940- H. F. PATTERSON EIAL 2,226,014

POWER TRANSMISSION Filed Nov. 26, 1937 5 Sheets-Sheei 3 INVENTORS BY AUGUST/N syRovY.

1940- H. F. PATTERSON ETAL I 2,226,014

POWER TRANSMI S SION H HERBERT E PflTTER80/V BYAUGUSTIN J. smovx A TTORNE Y Patented Dec. 24, 1940 UNITED STATES PATENT OFFICE rowan TRANSMISSION Herbert F. Patterson, St. Clair Shores, and Augustin I. Syrovy, Detroit, Mich asaignors to Chrysler Corporation, Highland Park, Micln, a corporation of Delaware Application November 26. 1937, Serial No. 176,588 17 Claims. (Cl. 74-262) Our invention relates to power transmission slon speed ratio, to efiect the fluid pressure necesmechanism and refers more particularly to imsary for the operation of the selected speed ratio provements in power transmission systems especontrolling device to control the torque transcially adapted for use in connection with motor mitted by the selected speed ratio.

vehicles, although notnecessarily limited thereto. An additional object of our invention resides in The invention, in certain more limited aspects, the provision Dressure regulating means provides improvements in the drive and control cludins a fl d p e s e elem c o lablv ior power transmission systems having epicyclic ing on the swash-plate of the well-known swashor planetary gear trains. With such planetary Plate pump to effect, in e pon e to e sele 1o transmissions, it is customary to arrange the of one of the transmission speed ratios, the fluid 10 gearing to provide for the desired number of pressure necessary f r t e op at of t s speed ratios between the engine and the vehicle lected speed ratio controlling device in completely ving ground wheels and such gearing is cuscontrolling the torque transmitted by the selected tomarily selected and controlled to obtain the de-' Speed osired driving speed ratio by actuating of any one Another Object of 0111 invention. in certain 15 of a group of transmission controlling devices more limited a p is to P ov de a pressure re usually consisting of reaction brake bands assouletins s. including a novel fluid pressu e ciated with and controlling the rotation of correelement controlled sw -Pl or the Wellsponding drums or similar elements of the various known swash-Plate p p that p es e 0P- gear trains. erating and levelling 01f characteristics of the 20 It is an object of our invention to provide a P p for efieeting n r p n e to the selection of novel and inexpensive means for eifecting, in reone 61 the transmission pe ratios t e fluid sponse to the selection of a speed ratio, the depressure necessary for the Operation of he sired degree of engagement of the selected speed l d Speed r o co t olling device in comp ratio controlling device of the transmission. 1y controlling t e torque transmitted y the e- 25 A further object of our invention, in certain le Sp d r omore limited aspects, resides in the provision of a Furt r j ts a d a anta s of our invenpump pressure regulating means which effects tion will be apparent from the following detail the desired fluid pressure for actuating the presdescriptions of several illustrative embodiments r operating means to properly control the of the principles of our invention, reference being 30 brake bands and clutches of the planetary gear had to the a p yin r win s in which trains or other corresponding types of transmjs- Fig. 1 is a side elevational view, somewhat diasions in response to the selection of a speed ratio grammatic in form, illustra 0 D r trflns controlling device of the transmission. In the mi n m h ni awholebroader aspects of our invention, th fluid pres- Fig. 2 is a detail elevational view showing the sure is preferably provided by a. suitable liquid manually controlled selector element and the medium such as oil, but the fluid pressure mediwell-known foot-operated brake and accelerator urn may be air under pressure greater or less pedals of a motor vehicle. than atmospheric pressure. Fig. 3 is a sectional view of the manually con- W A still further object of our invention is to protrolled selecting mechanism taken as indicated by 4 vide a simple and efllcient means for regulating the line 33 of Fig. 1. the well-known swash-plate pumpof such type Fig. 4 is a sectional view along the line l-l as is described and claimed in the co-pending apof Fig. 3. plication of Augustin J. Syrovy, Serial No. 29,788, Fi 5 is an enlarged sectional view taken apfiled July 5, 1935-in order to provide, in reproximately as indicated by the line 55 of Fig. 1. 45 spouse to the selection of a transmission speed Fig. 5A is an enlarged detail sectional view ratio, the proper maximum fluid pressure to effect ta en, alo t e e 5A5A o the degree of engagement of the selected trans- Fig. 6 is an enlarged sectional view taken along mission speed ratio controlling device necessary line 6-6 of Fig. 1 through the transmission and to control the torque transmitted by the selected fluid clutch. 50 speed ratio. Fig. 7 is a vertical sectional view through the Another object of our invention resides in the transmission, illustrating one of the speed ratio provision of a novel difierential balancing piston controlling devices and parts associated therewhich regulates the well-known swash-plate with, the section being taken as indicated by the pump, in response to the selection of a transmisline 1-"| of Fig. 6. 55

lating means therefor, the section being taken as indicated by the line I Ii I of Fig. 1.

Fig. 12 is a diagrammatic view illustrating the electrical system of control between the manually operated selector element and the fluid pressure control valve mechanism.

Fig. 13 is an enlarged detail sectional view taken approximately as indicated by the line |3-l3 of Fig. 6.

Fig. 14 is a side elevational view corresponding to Fig. 1 but illustrating another embodiment of our variable regulating means.

Fig. 15 is a fragmentary vertical sectional view somewhat diagrammatic and illustrating one of the planetary transmission speed ratio brake controlling devices, the section being taken along the line 15-15 of Fig. 14.

Fig. 16 is a detail sectional elevational view of the pressure pump and a portion of our pressure regulating means, the section being taken approximately as indicated by the line l6-l6 of Fig. 14.

Fig. 17 is a diagrammatic view illustrating the Figs. 14 to 16 fluid pressure system between the manually operated selector element and the operating means for the speed ratio controlling devices.

Fig. 18 is a partial diagrammatic view corresponding to Fig. 17 but illustrating another embodiment of our pressure regulating means.

Fig. 19 is a diagrammatic view which corresponds to Fig. 1'7 but illustrates still another embodiment of our pressure regulating means.

Referring now to the drawings, we have illustrated our invention in connection with a motor vehicle drive, this drive including a prime mover or engine A, a portion of which is shown in Fig. 1, a main clutch B driven from the engine, and a change speed transmission or gear box 0 driven from the clutch B. The drive passes from the transmission through the power take-off shaft 20, which, as usual, may extend rearwardly of the vehicle to drive the usual ground wheels (not shown).

The clutch B may be of any suitable construction for controlling the drive between engine A and transmission C, this clutch being illustrated in Fig. 6 in the form of a fluid coupling type having the usual driving and driven cooperating vane members 21 and 22 respectvely. The driving vane member 2| is carried by the engine flywheel 23, the latter being connected as usual with the rear end of the engine crankshaft 24. The driven vane member 22 is splined to a hub 25 which in turn is splined at 26 on the forward end of the driven shaft 21. This driven shaft extends rearwardly to drive the power take-oil shaft 20 through the intermediary of the various gear trains of transmission C.

Where the power means for operating the transmission is afforded by a fluid such as oil under pressure, the pump for placing the oil under pressure is preferably operated from the engine to maintain the fluid pressure even when the pump is idling. It is therefore preferred to provide a pump drive from the driving clutch member 2| rather than the driven clutch member 22 inasmuch as the latter may be stationary under certain conditions of vehicle operation such as. s

when the vehicle is standing still with the engine idling.

This pump drive may be provided by reason of a driving sleeve or hollow shaft 23 mounted on the shaft 21 but rotatable independently thereof. The sleeve 23 has a hub or flange 30 connectedat 31 with the driving vane member 2| of the clutch B so that even when the driven vane member 22 is not being operated from the driving vane member 2|, the sleeve 29 will be rotatably driven from the engine crankshaft 24 and flywheel 23. The pump drive from sleeve 23 will be more apparent hereinafter.

We have illustrated the fluid type of clutch B since a clutch of this character has a number of advantages in connection with a transmission of the planetary gear type C and in further connection with our arrangement of vehicle driving controls which will be presently described more in detail. Among the advantages of the fluid type of clutch are the provision of a smooth drive for the vehicle through the planetary transmission, relatively high power driving efllciency, automatic release of the drive between the engine and transmission when the engine is idling, and with the transmission manipulated to establish one of its driving gear ratio settings, and other well known favorable characteristics. We desire to point out, however, that other types of clutches may be employed to control the drive between engine A and transmission C within the broader aspects of our invention. For example, the well known type of friction clutch may be employed and manually operated or automatically operated by the well known commercial type of vacuum clutch releasing mechanism as will be readily understood.

We have illustrated the change speed transmission C as the epicylic or planetary type, this general form of transmission being well known in the art and, as usual, includes a plurality of transmission speed ratio controlling clutches or brakes 32, 33, 34 and 35, these braking controlling devices being respectively adapted to actuate the transmission in its first speed ratio or low gear,

second speed ratio or intermediate gear, third speed ratio or direct drive, and reverse drive. Other speeds may be provided as desired.

The typical brake device 32 illustrated in Fig. '1 consists of an outer band 36 which substantially surrounds the rotary element or drum 31, the band being provided with friction braking material 38 carried by the band and adapted for frictional engagement with the drum 31. The band 36 has its ends formed with laterally projecting actuating flanges 33 and positioned adjacent each other, means being provided to move the band ends toward each other to contract the hand 36 for causing the friction material 38 to brake rotary drum 31, the band having suflicient inherent resilience to expand away from contact with the drum when the actuating means is relieved at the flanged ends 33 and 43 In Fig. 7 the low speed ratio braking device 32 is illustrated in its inoperative position whereby the (111111131 is free to rotate through operation of the planetary gear set 4| somewhat diagrammatically illustrated in association with the drum 31. When the braking device 32 is actuated by contracting the band 36, the drum 31 is held against rotation, the driven shaft 20 in such instance being operated through the planetary gearing 4| to provide the low speed drive for the motor vehicle.

In order to anchor the band 35 and to substantially equalize the braking forces applied to drum 31 around the periphery thereof and thereby substantially avoid a tendency toward lateral loading of the drum and planetary gearing transverse to the axis of the drum, we have provided the band with a circumferentially spaced pair of anchoring flanges 42. These flanges are connected through links 43 with the levers 44 pivotally mounted at 45 with the supporting bracket 46 of the transmission side cover casing 41, the levers 44 being interlocked at 48 so that movement of one of the flanges 42 will betransmitted through the pivotal levers 44 and the links 43 to the other portion of the band associated with the anchoring device. The links 43 are thus pivotally connected at their opposite ends respectively with the anchors 42 and levers 44.

The third speed clutching controlling device 34 is arranged for a direct drive through the transmission and differs somewhat from the braking devices 23, 33 and 35 in that the controlling device 34 has its rotary controlling element 50 adapted for clutching action in a well known manner by frictional engagement through the discs by an axially movable clutching member 52. The latter clutching member is thus engaged by the yoked end 54 of an actuating lever 55 pivotally mounted by a pin 56 suitably supported in the transmission casing. ,On the opposite side of pivot 58 the lever 55 is provided with a step actuating portion 59, the purpose of which will presently be more apparent.

The transmission casing portions 58 and. 58 are respectively provided with the vertically spaced inwardly extending supporting brackets 62 and 83, respectively, these brackets being formed with coaxial splined openings 84 and55, respectively. Splined within these openings are the nuts 85 and 61 which are axially and oppositely threaded. to receive the correspondingly threaded ends 58 and 69 of an operating oscillatory shaft or screw 10. c

The shaft extends through openings H and 12, respectively, formed to open laterally in the aforesaid band ends 39 and 40, these openings having considerable clearance with shaft 10 so as not to bind on the shaft when the band is contracted and expanded. In order to transmit the thrust of the nuts 56 and 51 to the flanges 39 and 40 so as to relieve distorting loads on the shaft 10 and parts associated therewith, each nut operates a sleeve 13 having a curved face 14 engaging a curved face of band end 39 or 40. The

ance indicated at 16 with the shaft 10.

The operating shaft 10 of the low speed braking device 32 has its portion thereof intermediate the band ends 39 and 48 formed with a gear 11, the means for oscillating shaft 10 through the gear I1 being hereinafter more particularly described.

In the operation of the low speed controlling device 32 as thusfar described, it will be apparent that when the shaft 10 is given a rotary movement, such movement operates through the oppositely threaded ends 88 and 83 of the shaft 10 to cause the nuts 66 and 81 to move inwardly toward each other in their splined openings 54 and 35 respectively, this movement acting through the sleeves 13 to contract the band ends 39 and 48 whereby the low speed drum 31 has its rotation checked for establishing the low speed drive through the transmission. When the shaft (II is rotated in the opposite direction, the nuts 33 and 51 are moved away from eachother and th band 38 is expanded to permit the drum 31 to again rotate and thereby relieve the drive through the transmission controlling device 32.

In order to avoid repetition we have not illustrated all of the details of the brake operated means associated with the controlling devices 33 means are similar to that described in connection and 35, it being understood that suchoperating means are similar to that described in connection with the controlling device 32. For convenience of reference the operating shaft or screw for the reverse speed braking device is designated as 18 and the corresponding shaft forthe second speed braking device 33 is designated as 10". The gears associated with these screw shafts are respectively designated as 11* and As will be more apparent presently, the gears 11, 'I'I' and H and lever end 53 are adapted to be selectively operated in order to selectively control the engagement and release of the respective speed ratio controlling-devices 32, 35, 33 and 34.

- The transmission casing is adapted to support in a forward opening I8 the reciprocating and oscillating rack or actuating shaft D. The rear bearing for shaft D is provided by a member 19 which is disposed in a suitable opening 80 in the rear end wall 8| of the transmission casing 8|, the rear end of the actuating shaft D being also supported by a piston for reciprocating the shaft and which will presently be referred to in detail. This actuating shaft D has a series of teeth forming a rack adapted to be brought into operative association with each of.the screw gears, these racks being designated at 82, 83 and 84 for respectively operating the screw gears 11, 11, and 11 The forward end of shaft D is further provided with a third speed actuating projection 85 adapted for engagement with the lever shoulder 59 for operating the third speed controlling device 34. It will be noted that the racks and projection 85 are longitudinally spaced along the shaft D and that they are also spaced circumferentially of the shaft whereby upon progressive rotation of the shaft only one of the racks and the projection 85 will engage its associated screw gear or lever 55 at any time.-

In Figs. 6 and 7 it will be noted that the shaft D is positioned so that the low speed rack 82 is in position for operating the low speed gear TI and when the shaft D is moved forwardly or to the left as viewed in Fig. 6., the low speed screw 10 will be rotated to cause the aforesaid braking operation of the low speed controlling device 32 for establishing the low speed drive through the transmission. It will furthermore be noted that with the low speed rack 82 in the position illustrated, the remaining racks I3, 84 as well as pro- J'ection 85 are free from engagement with their respective associated gears 11, 11 and the lever 55. From Figs. 6 and 7 it will be noted that the shaft D has a space longitudinally and circumferentially between the second speed rack 84 and the direct drive projection 85, this space being designated as the neutral space N so that when the shaft is positioned with this space facing the screw gears, each of the racks as well as projection 85 will be free from contact with their associated screw gears and lever 55, and the transmission will be in neutral at which time the varibus braking devices 32, 33, 34 and 35 are released.

In order to selectively rotate the rack D for selectively engaging the racks and projection thereof with the respective screw gears and lever 55, and also for axially operating the shaft in the various positions of selective adjustment, the

' following mechanism is provided.

Rearwardly adjacent the reverse rack 93, the shaft D is provided with a circular rack or gear 95 meshing with a segmental rack 91 rotatably fixed with a shaft 99, best shown in Fig. 7, this shaft being rotatably journaled by a bearing 39 carried by the transmission side cover 99. The shaft 99 has fixed thereto, outwardly of the transmission cover, a lever 9I connected at 92 (see Fig. l) to a Bowden wire operating mechanism 93.

The Bowden wire operating mechanism 93 extends forwardly for pivotal connection with a. ball end 94 of a lever assembly 95 secured to a tubular shaft 99 as shown in Figs. 5 and 5A. The forward end of the Bowden mechanism has a guide 91, provided by the bracket 99 rigidly secured to the outer stationary tubular housing 99 com-- prising the steering post, as best shown in Fig. 1.

A yielding connection is preferably provided at some convenient point between the manual selector element, which will be shortly described, and the segmental rack 91 for rotatably adjusting the shaft D. We have illustrated this yielding connection in Fig. 5A intermediate the lever ball end 94 and the forward end of the Bowden wire mechanism 93. The wire 93 is anchored at its forward end to a housing I99 provided with preloaded oppositely acting springs I M and I92 which respectively act against the ball seats I93 and I94. The springs MI and I92 have sufficient rigidity so that normally they provide a rigid connection between lever 95 and Bowden wire 93. However, if for any reason the manually operated adjusting mechanism for the shaft D should bind at any point, the mechanism will be protected during any manual adjustment of lever 95 under such conditions by reason of the ability of springs IN and I92 to yield. This yielding connection is therefore in the nature of a safety device for the manually controlled selector operating mechanism. The hollow operating shaft 96 extends within the housing 99 and is suitably rotatably journaled therein.

Rotatable within the hollow shaft 96 is the hol low steering shaft I91 operably connected at its upper end to a steering wheel I98 and adapted for operable connection at its lower end to the usual steering mechanism for the front ground wheels of the motor vehicle (not shown). The hollow operating shaft 96 extends upwardly to the point preferably just below the steering wheel I99 to the manually controlled device generally designated at E for selectively controlling or manipulating the transmission speed ratios as will be presently more apparent.

Returning now to Fig. 6, the selector rack shaft D has its rear end adjacent the circular rack 36 provided with a groove I99 adapted to receive the fiange II9 of the fluid pressure operating piston assembly III adapted for reciprocal movement in the cylinder II2 which is a part of a casting II3 best illustrated in Figs. 8 and 9 as attached at II4 to the rear wall of the transmission. The piston III provides the actuating member of the power operating means G for moving shaft D under power to engage the various brake bands and the direct speed clutch 34.

, netic material.

mover means F preferably in the form of a compression coil spring surrounding the rear end portion of shaft D between the fixed abutment provided for the bearing member 19 and acting on piston III. In Fig. 6 it will be noted that the 5 bearing member 19 is conveniently held in position by clamping the same between the rear casing wall ll of the transmission and the casting assembly II3.

The piston III has a fiexible sealing cup II5 adapted to seal the piston against escape of the fiuid forwardly of the cylinder II2, the cup II5 bearing against the walls of the cylinder under the action of thefiuid pressure introduced to the pressure chamber H6. The sealing cup is held in place by the rearwardly extending threaded reduced fastener or nut III. Fluid, such as oil under pressure, is introduced to the pressure chamber II5 as best shown in Fig. 9, through a passage II 9 leading to the valve controlled chamber or cylinder I29 which slidably receives the fiuid pressure supply controlling valve I2I.

The cylinder I29 is supplied with oil under pressure through a passage I 22 which receives the oil by a conduit I23 formed in the transmission casing casting. The conduit I23, as best shown in Fig. 1, leads to the delivery side of a swash-plate type pump H driven from its location in the oil storing sump or reservoir I24 of the transmission casing by reason of the shaft I25 provided at its forward end by a driving gear I29. This gear meshes with an idler gear I21 which in turn meshes with the driving pinion I28 (see Fig. 6) carried on the rear end of the driving sleeve 29 which, as aforesaid, is fixed to the fluid impeller 2|.

A valve guide porting member I29 is pressed into the cylinder I29 so as to be fixed therewith, this porting member having annular conduits I39 and HI, respectively, communicating with the passages I22 and H9. The annular passages I39 and I3I are also respectively provided with the inwardly extending ports I32 and I33 adapted for control by the valve I2I. This valve has a sliding fit within the cylindrical bore I34 01' the porting member I29 and extending axially through the valve with sufficient clearance to prevent binding thereof, is a valve operating rod I35 preferably of brass or other non-mag- The rod I35 extends forwardly of valve HI and is provided with a stop I39 adapted to limit forward movement of valve I2l under the influence of a spring I31 which operates between a valve spring abutment I33 and a rearfixed abutment I39, the latter having associated therewith the fiuid pressure sealing washers I49 acting against the threaded stem I H of the electrical solenoid I42.

The rear end of valve operating rod I35 is connected at I43 with thearmature I44 of solenoid I42, the armature being adapted for reciprocation in the solenoid cylinder T45 having the rear abutment I45. Any fluid which may leak rearwardly beyond the valve I2I is adapted to drain downwardly from the portion of casting II3 which encloses the valve operating spring I31 by reason of the drain -conduit I41, .this conduit then extending forwardly to the main body of the transmission where the oil is permitted to drain back to the reservoir I 24. A further conduit I49 7 is adapted to return the oil from operating cylinder II5 back to the reservoir, this conduit I49 ilipfning rearwardly to the forward end of valve The valve I2I has the reduced valving portion 7| I49 adapted to place the conduits I22 and H9 in communication when the valve is in its forward position under the influence of spring I31. In the drawings, the parts are shown in their positions for operating the low speed controlling device 32, the valve I2I being positioned forwardly so that the fluid pressure is just being delivered from the supply conduit I22 to the conduit H9 and the pressure chamber II6 of the cylinder II2. When the valve I2I moves rearwardly under the influence of solenoid I42, as will be presently more apparent, the spring I31 will be compressed and the reduced portion I49 will no longer provide communication between conduits I22 and H9 to supply fluid pressure from the pump H to operate the piston I II and selector rack shaft D forwardly for actuating one of the speed ratio controlling devices 32, 33, 34 or 35, depending on the rotative selective adjustment of the selector rack shaft, as will be presently more apparent.

The function and operation of the manually controlled selector mechanism E in relation to the selector rack shaft D will now be further described.

Secured to the upper end of the hollow operating shaft 96, as best seen in Fig. 4, is an annular collar I50 having an integral laterally extending projection II providing an abutment for a spring I52 which has its lower end yieldingly acting against an intermediate portion of a manually operated selector element or lever I53. It will be noted that the extension I5I projects through an arcuate opening I54 of the fixed housing 99 to accommodate oscillating adjustment of the extension I5I.

The inner end of selector lever I53 is pivotally mounted at I55 to an intermediate portion of the collar extension I5I so that the selector lever may have vertical movement on pivots I55 relative to the extension I5I but when lever I53 is moved around the axis of the steering post housing 99, the collar I50 together with its extension I5I and the shaft 96 will be rotatively moved as a unit.

Fixed on the upper end of the housing 99' is a housing I56 preferably in the shape of a sector. The outer end of this housing has a downwardly extending flange I51 provided with an arcuate opening I 58 through which the lever I 53 extends for arcuate adjustment. The outer end of the selector lever is provided with a knob or handle I59 adapted for convenient grasp by the hand of the motor vehicle driver.

The outer curving edge of housing I56 is preferably formed with a number of legends characterizing the various positions of manual adjustment of selector lever I53 depending on the number of stations of adjustment for this lever. In the particular embodiment illustrated, the selector lever I53 is adapted to have five positions of adjustment l60, I6I, I62, I63 and I64 bearing the legends indicated in Fig. 3 designating the lever positions corresponding to first, second, third, neutral and reverse conditions of control for the transmission.

The flange l51 of housing 156 carries an arcuately arranged switch mechanism below the selector lever I53, this mechanism being best illustrated in the wiring diagram of Fig. 13. This switch comprises an arcuate floor I65 provided with a series of grooves or notches I66, I61, I68, I69 and I corresponding respectively to the positions of selector lever I53 when adjusted to the stations I60 to I64, inclusive. The upper sides of the aforesaid notches are preferablychamfered or beveled, as shown in Fig. 13, and the portion of selector lever I53 engageable with these notches is likewise beveled as'indlcated at "I.

When the operator desires to select any condition of control of the transmission, he swings the selector lever I53 into the desired position, the spring I52 yieldingly urging the selector lever downwardly into engagement with one of the notches of the switch member I65.

Referring now to the wiring diagram of Fig. 12, a. plurality of switches or contacts I12 for each of the notches of the switch member I65 are adapted for operation by a stem I13 slidable in an opening I14 communicating with each of the switch notches. When the selector arm is located in any of the switch notches, one of the stems I13 associated with such notch is engaged by the selector lever and is pushed downwardly by the spring I52 to break the current through the wire I which connects all the switches I12 in series. Each switch I 12 has a spring I16 associated therewith for restoring the switch to its contacting position and raising its stem I13 as soon as the selector lever is moved out of one of the notches. The wire I15 connects with one terminal of a storage battery I11, the other end of the wire I15 being connected to the windings I18 of the solenoid armature I44 aforesaid, which is grounded at the other terminal of the battery I11.

The manually controlled selector operating mechanism is practically instantaneous in its response to selective adjustment of the lever I53 and the diiferent selections may be made as rapidly as desired. In the general operation of the selector mechanism E for changing the transmission speed ratio, the operator moves the selector lever I53 from one of the station notches in the switch member I65. Just as soon as the selector lever is moved from one of the notches, the switch I12 associated with such notch will be closed, thereby inducing an electrical circuit through the solenoid windings I18 for causing the solenoid armature I44 to move rearwardly against the abutment I46. This rearward movement of the solenoid armature will adjust the valve I2I rearwardly to place the fluid pressure chamber II6 of cylinderl I2 in communication with the reservoir discharge conduit I48 whereupon the spring F will move the shaft D rearwardly to release any of the controlling devices 32 to 35 which might have been in operation. This entire phase of the operation takes place very,quickly during the initial part of adjustment of the selector lever out of one of the notches of the switch member I65. The selector lever I 53 may then be moved into any other station of control and dropped into the corresponding notch for such position.

When the selector lever is so released it will be apparent that one of the switches I12 corresponding to such newly selected position will be opened, thereby interrupting the electrical circuit through the wire I 15 to the solenoid windings I18. At such time the spring I 31 will immediately act to move the valve HI and the armature I44 forwardly to establish communication between the fluid pressure supply conduit I22 and the pressure chamber II6. This will immediately cause a forward movement induced by the fluid pressure on the shaft D for operating one of the selector controlling devices which might have been selected for the new position or else for operating the shaft D without causing any movement of any of the speed ratio controlling devices in the event thatneutral was selected.

Returning now to the aforesaid cycle of operation and to the point where the selector lever I88 was described as having been moved out of one of the notches preparatory to movement thereof into a newly selected notch, just as soon as the solenoid armature I44 moves rearwardly'to operate the valve I2I to vent the pressure chamber II8, it will be apparent that the fluid pressure load is removed from the shaft D which is now in its rearward position so that arcuate movement of the selector lever I88 will operate through the hollow steering mechanism H2, and sector 81 to rotatably adjust the shaft D into a new position for actuation of one of the speed ratio controlling devices. The mechanism operates almost instantaneously so that there is practically no resistance to immediate arcuate adjust of selector lever I88 from a position in one of the notches although any binding tendency experienced at the shaft D during the initial or other tendency to move the shaft will be taken up yieldingly through the Bowden wire connection shown in Fig. 5A.

Referring now to the details of the pump H and our pressure regulatingmeans, the pump assembly includes a casing structure I18 fixed to the transmission structure as illustrated in Figs. 1 and 11. The casing I18 receives the pump drive shaft I28 aforesaid which is suitably journaled at I88 and I8I by the casing.

As illustrated the gear I28 on the shaft I28 is in constant mesh with the idler gear I21 which in turn is drivingly connected with the fluid-impeller-associated driving pinion I28. A ported cylindrical member I82 is suitably flxed to the casing I18, the member I82 having inlet and outlet passages I88 and I84 respectively for the fluid, such as oil, admitted to the pump H and delivered therefrom under pressure. The inlet I88 is in suitable communication with the fluid in the reservoir I24. I

Tightly pressed into a cylindrical opening I85 of the ported member I82 is a cylindrical port seat body or ring I88 journaling the adjacent end of the shaft I25, this body having inlet and outlet passages I81 and I88 communicating radially at one end with the passages I88 and I84 respectively. The other ends of the passages I81 and I88 form the well known circumferentially spaced arcuate inlet and outlet ports respectively for communication with the inlet and outlet ports of the pumping cylinders as will presently be apparent.

A pump rotor I88 is drivingly connected to the shaft I28, and carries a plurality of circumferentially spaced cylinders I88 opening inwardly toward a wabble or swash-plate I8I, a cylinder head portion I82 of the rotor having a port I88 for each cylinder.

A piston I84 is adapted to reciprocate within each cylinder I88 and is urged inwardly by a spring I88 into contact with the swash-plate I8 I, the inner rounded end of each piston yieldingly engaging an outer ring I88 of the swash-plate. This ring is supported by a bearing I81 carried by a swinging arm I88 pivotally supported at I88 from the casing I18. The swash-plate I8I carries an extension 288 which is adapted to be controlled by a pressure piston 28I in its swinging movement aboutthe support I88 for levelling-off the plate I8I and minimizing or eliminating reciprocation of the pistons I84. The fluid under pressure is led to a suitable point of usage from the pump outm in its Fig. 11

post shaft I81, Bowden wire munication with the conduit I28.

As the shaft I28 drives the rotor I88, with plate position for maximum stroke of the pistons I 84, approximately half the pistons I84 are moving inwardly drawing in oil through their inlet port and ports I88 associated therewith, while the remaining pistons are discharging Oil under pressure through their associated ports I88 and outlet port for conveyance through the passage 282 in the well-known manner.

When the pump H is initially operated, the

pressure of the oil delivered through the passage 282 at the same time communicates through a lead-oil passage 282 with a cylinder 28! of a pressure casing 284 within which the piston 28I with a suitable sealing member 288, attached thereto by a fastener 288, is adapted to provide a fluid pressure space 281. The casing 284 is suitably fixed to the pump casing I18 as by fasteners 288 which preferably are also adapted to hold a sealing member 288 that provides a second fluid pressure space 2I8 which is supplied fluid pressure to a predetermined amount through a conduit 2| I under certain conditions as will hereinafter be more apparent. The conduit 2 is so positioned that the piston 28I in its movement forwardly to level off the plate I8I will not uncover the conduit 2| I to the pressure space 281.

The effective area of the piston 28I in sealing the pressure space 281 is such that when a predetermined fluid pressure is substantially built up in the passage 282, providing no fluid pressure has been introduced into the pressure space 2" through the conduit 2, the piston will move forwardly to progressively level off the plate I8I until the pistons I84 are substantially motionless so far as reciprocation is concerned, assuming of course that oil under pressure is not being relieved from the delivery system. Any minor leakages which might be present in the delivery system will require only a small movement of the pistons to maintain the maximum desired oil pressure in the passage 282.

To automatically control the fluid pressure of the pump H in response to the selection of the various speed ratio controlling devices, we prefer to use a rack actuated valve 2I2 which is illustrated as adapted to provide a predetermined fluid pressure to actuate the flrst and reverse speed ratio controlling devices 32 and 35 respectively, but we desire to point out that similar'controlling means may be provided for the other speed ratio controlling. devices without departing from the scope of our invention.

The valve 2I2 is adapted to reciprocate within a cylinder 2I3 of a projection or extension 2 I4 of the casing 8| at right angles to the rack D, a suitable resilient means such as a spring 2I5 suitably housed within the cylinder 2I8 urging the valve against the rack. An elongated cam surface 2I8 (best shown in Fig. 13) is formed on the rack D and is continuously adapted while the rack is in its reverse or illustrated flrst speed positions to place in communication through a valve portion 2I1 of the valve 2 I2 a pressure conduit 2I8, branching off the passage 282, and the delivery conduit 2I I leading to the pressure space 2 in communication with a relief passage 228 7 open to'the oil reservoir I24.

its illustrated position With the valve 2I2 in of Fig. 6 the fluid pressure from the passage 202 is admitted into the conduit 2 communicating with the second fluid pressure space 2"]. The area of the piston seal 205 is sumcient to efiect through the pressure within the pressure space 201, providing there is only atmospheric pressure within the space 2 ID, a leveling on 01' the swashplate I9I at a predetermined fluid pressure delivered by the pump H through passage 202. The cross-sectional area of the piston 2lII is suflicient to effect, through the fluid pressure admitted into the space 2III to oppose the fluid pressure in the space 201 tending to move the piston 20I forwardly to level 011 the swash-plate, a levelingofl' of the swash-plate at another predetermined fluid pressure delivered by the pump which is preferably higher than the pressure at which the plate I3I levels off when the valve 2I2 is in its other position against the normal portion 2I9 of the rack D. We have found it desirable to use a higher fluid pressure to actuate the first and reverse speed ratio controlling devices 32 and 35 respectively to hold satisfactorily the drums 31 inasmuch as higher torque is transmitted by these speed ratios than by the other speed ratios. However, we wish to point out that means similar to the valve 2 I 2 may be used to control the operating fluid pressure for actuating any 01' the other controlling devices 33 and 34 without departing from the scope of our invention.

The position of the rack D, as determined by the condition of the selector handle I53, thereby controls through the cam surface 2I6 the posie tion of the valve 2I2 to effect a predetermined high fluid pressure level-off of the pump H for the reverse and first speed ratios, and a predetermined low fluid for the second and direct speed ratios. Upon selection of the second or direct speed ratios; by the vehicle driver the rack D is rotated in response to movement 01' the selector lever I53 to place the rack normal portion 2I9 adjacent the valve 2I2 to cause a closing of the conduit-2I8 and an opening of the passage 220 to relieve the fluid pressure in the space 2I0.

The face of the cam surface 2I6 can be made continuous between its reverse speed ratio position and its illustrated first speed ratio position inasmuch as none of the controlling devices 32 to 35 are actuated when the selector lever I53 is in its neutral station I 69 interposed between the first and reverse speed stations I 50 and I64 respectively.

One feature of our invention resides in the simple control that is possible with our novel transmission system, onepreferred embodiment of this control being illustrated in Fig. 2 wherein it will be observed that the selector lever I53 is positioned for manipulation laterally-to the right of the steering wheel I08 for effecting a change in the condition of the transmission. Our transmission provides for convenient manipulation of the motor vehicle by providing the engine throttle control or accelerator pedal 22I preferably at the right hand side of the steering post 99 so that it may be manipulated by the right foot of the driver. On the same side of the steering post is a pedal 222 which is adapted to operate the wheel brakes of the motor vehicle. Our illustrated transmission is wholly responsive to the various positionings of the selector lever I53 by the vehicle driver, and our fluid pressure regulating means is selectively controlled thereby without repressure level-off of the pump quiring additional controls or adjustments by the driver.

In the operation of the illustrated transmission the vehicle driver merely manipulates the selector lever I53 to obtain the desired speed ratio with the desired engagement characteristics of the speed ratio controlling device for the selected speed ratio. The selector operating mechamsm is practically instantaneous in its response to selective adjustment of the lever I53 and the different selectionsmay bemade as rapidly as desired.

When the operator moves the selector lever I53 from one of the station notches in the switch member I65, the switch I12 associated with such notch will be closed-thereby inducing an electrical circuit through the wire I15 to the solenoid windings I18 for moving the solenoid armature I rearwardly. This rearward movement of the solenoid armature will adjust the valve I2I rearwardly to place the fluid pressure chamber III; of cylinder H2 in communication with the reservoir discharge conduit I48 whereupon the spring F will move the shaft D rearwardly to release any of the controlling devices 32 to 35 which might have been in operation. The selector lever I53 may then be moved into any other station of control and dropped into the corresponding notch for such position.

When the selector lever is so released, it will be apparent that one of the switches I12 corresponding to such newly selected position will be opened-thereby interrupting the electrical circuit through the wire I 15 to the solenoid windings I18. At such time the spring I31 will immediiately act to move the valve I 2I and armature I forwardly to establish communication between the fluid pressure supply conduit I22 and thepressure chamber H6. This will immediately cause a forward movement induced by the fluid pressure on the shaft D for operating one of the selector controlling devices 32 to 35 which might have been selected for the new position or else for operatingshait D without causing any movement of any of the speed ratio controlling devices in the event that neutral was selected.

' Upon moving the selector lever to a position adjacent the first or the reverse speed stations I60 and IE5 respectively, the rack D is rotated in the earlier described manner to engage the gear 11 with the rack 82 for eflecting first speed or to engage the gear 11 with the rack 83 for efiecting reverse speed. During this interval the cam surface 2I6 is simultaneously rotated to hold the valve 2I2 in its first and reverse speed position at a which time the relief passage 220 is closed and the fluid pressure from the pump H communicates through the conduits 2H and 2I8 with the space 2I0 to oppose the pressure in space 201 tendingto level ofi the swash-plate I9I. This introduction of fluid pressure to the space 2I0 makes it necessary for the pistons I 94 of the pump to reciprocate until additional fluid pressure is created and led to the space 201 suificient to overcome the fluid pressure in the space 2H) and level oil the swash-plate. The pump H is practically instantaneous in its response to this movement of the valve 2I2 and rapidly builds a predeter-. mined fluid pressure before levelling off.

As soon as the selector lever is dropped into the corresponding notch for thenewly selected position, which may be as soon as desired, one of the switches I12 corresponding to such newly selected position will be opened, as described earlier to cause a forward movement of the rack induced by the fluid pressure in the chamber I I3. It is obviously evident that the fluid pressure in the chamber H6 is increased to a predetermined amount before the pump is levelled off, and thereby the selected controlling device 32 or 35 is actuated to 'hold the drum 31 against undesirable s ippa e.

When the vehicle operator desires to drive the vehicle in the second or direct speeds of the illustrated transmission he adjusts the selector lever I53 to a position adjacent the second or the direct speed stations I6I and I62 respectively, the rack D is rotated in the earlier described manner to engage the gear 11 with the rack 84 for eflecting second speed or to actuate the direct drive clutch 33 for effecting the direct drive. During this interval the cam surface 2I6 is simultaneously rotated to allow the spring 2 I 5 to urge the valve 2 I 2 into its second speed and direct drive position against the normal portion 2 I9 of the rack.

During the movement of the valve 2|! by the spring 2|! the conduit 2I8 is closed as the relief passage 220 is opened to the conduit 2 so that the space 2| 0 is vented to relieve the pressure accumulated therein when the selector lever I53 has been opposite the neutral, first or reverse stations I63, I60 and I64 respectively prior to the newly selected position thereof. When the valve 2I2 is against the rack normal portion 2I9 the fluidpressure from the pump H communicates through the passages 202 and 202 with the space 201 to level off the plate I9I when a predetermined fluid pressure is provided by the pump with which to actuate .the second or the third speed ratio controlling devices 33 and 34.

Upon dropping the selector lever into the corresponding notch I61 or I68 for the newly selected position, one of the switches I12 corresponding to such newly selected position, one of the switches I12 corresponding to such newly selected position will be opened, as described earlier, to cause a forward movement of the rack induced by the fluid pressure in the chamber I I6. The maximum fluid pressure thereby provided in the chamber I I6 is suii'flcient to cause the pump to level off at a predetermined fluid pressure adequate to actuate the selected controlling device 33 or 34 sufllciently to hold the drum 31 against undesirable slippage.

creased fluid pressure required by the low and reverse speed ratio controlling devices 32 and 35 respectively to accommodate the comparatively higher torque transmitted by these speed ratios.

Our fluid pressure regulating means provides, in response to the selection of a speed ratio, the degree of engagement of the selected transmission speed ratio controlling device necessary to control the torque transmitted by the selected speed ratio gear train. As a result of the function of our regulating means the various speed ratio controlling devices 32 to 35 are actuated sufliciently to control the torque transmitted by the selected speed ratio gear train, which control of the fluid pressure delivered by the pump H effects better operating characteristics than does the use of a uniform fluid pressure for actuating any of these controlling devices. Furthermore, the use of the desired fluid pressures for operating the controlling devices reduces the wear on the bearing surfaces of the pump inasmuch as the pump operates only to furnish a predetermined fluid pressure for each speed ratio. The fluid pressure required to satisfactorily actuate the second and third speed ratio controlling devices 33 and 34 respectively is lower than that required for the other speed ratios, and inasmuch as the vehicle driver ordinarily operates his vehicle in second and third speeds for long periods, the pump H has a comparatively low fluid pressure to maintain.

Referring now to the modified embodiment illustrated in Figs. 14 to 17, our pump pressure regulating means is illustrated with a pressure system for a power transmitting device of the same general character asthat of the earlier described embodiment except that the pressure medium is selectively admitted to individual pressure cylinders for actuating tfiecperating means of each speed ratio-controlling device. Parts of similar function but different construction have been indicated by primed W reference characters.'

The illustrated vehicle drive includes the prime mover or engine A, the fluid coupling clutch B" driven from the engine, and the change speed transmission 0' driven from the clutch B. During the operation of the transmission (3 the drive passes from the transmission through the power take-01f shaft 20'.

It will be noted that the change speed transmission C is of the epicyclic or planetary type. As usual, this transmission includes the transmission speed ratio controlling devices 32", 33?", 34" and 35", these controlling devices being respectively adapted to actuate the transmission in its first speed ratio or low gear, second speed ratio or intermediate gear, third speed ratio or direct drive, and reverse drive.

The controlling devices 32' to 35" are adapted to act on transmission elements associated therewith and usually embodied in the form of a rotary drum like the drum 31, which is illustrated in Fig. 15 in association with the transmission controlling device 32' for the first speed. Inasmuch as the form and arrangement of these planetary gear trains are well known in the art, the details are omitted from this disclosure.

The speed ratio controlling devices 32' to 35" are, for the most part, similar in construction and operation and the following description of the details of the controlling device 32 illustrated in-Fig. 15 is typical of the other brakes. In Fig. 15 the drum 31 is normally rotated by the planetary gearing l'I associated therewith when the transmission C is not in its first speed driving condition, and when rotation of the drum 31 is'prevented by the braking mechanism associated therewith, then the drive through the transmission takes place for the first speed gear ratio according to the well known practice for planetary gearings of the general type illustrated.

To brake the drum 31, the band. around the drum provides ends 223 and 224 normally separated by a spring 225. The band 36 is provided with the brake lining 38" adapted to contact with the drum when the ends 223 and 224 of the brake band are forced toward each other to contract the band. The band 36 is anchored in any suitable manner (not illustrated) and a suitable brake actuating mechanism is provided for each of the bands such as the actuating mechanism illustrated in Fig. 15.

With each of the controlling devices 32 to 35'" is associated a cylinder. One of these cylinthe respective band ends 223 and 224 by suitable links 229 pivoally supported at 230. The cylinder 226 has a fluid pressure inlet 23! adapted to admit fluid under pressure to the space between the pistons 221 and 228 in order to actuate these pistons away from each other as shown in Fig.. 15 in contracting the brake band to arrest rotation of the associated controlling drum 31. Upon release of the fluid pressure, the spring 225 will act to space the brake band 36" from the drum 31, pistons 221 and 228 being also restored and the fluid pressure being displaced from the cylinder 226 by way of the opening 231.

In order to selectively control the supply of fluid under pressure to the actuating mechanism of each of the various speed ratio controlling devices provision has been made for a fluid pressure control and distributing system, illustrated in somewhat diagrammatic form in Fig. 14. I The pump H is suitably located to draw the fluid from the reservoir I 24" through the passage 183", the fluid under pressure being discharged from the pump through the high pressure passage I84 leading to a valve casing 232 of the selective controlling means herein illustrated in the form of rotary distributing valve means J.

A valve 233 of the valve means J cooperates with the casing 232 to provide a fluid pressure supply space or chamber 234 and a low pressure space or chamber 235. The supply chamber 234 delivers oil under pressure from the high pressure passage I84 through a passage 236 extending through the valve to a distributing outlet 231 illustrated in Fig. 14 as registering with a conduit 238,- the outlet being also adapted for selective alignment with further conduits 239, 240 and 24!. The casing 232 has an uninterrupted portion 242 intermediate the conduits 238 and 241 so that when the outlet 231 is adjusted to a position opposite the portion 242, the fluid in the passage 236 will not escape, this position being the neutral setting of the valve 233.

The low pressure chamber 235 is continuously open to a conduit 243 which is arranged below the plane of oscillatory movement of the outlet 231, the conduit 243 communicating with. the reservoir 124". During movement of the valve 233, the high pressure chamber 234 is continuously in communication with the oil pressure delivery passage 236, and the low pressure chamher 235 is continuously in communication with the return 243..

The distributing valve means J is adapted to be manually adjusted by the vehicle driver. The stationary selector segment I56 is conveniently mounted on the steering post 99", the segment having a plurality of notches for advising the operator of the setting of the hand-operated selector lever I53 pivotally mounted at 244 in association with the segment I56". The selector lever I53 has a certain amount of resilience so that when moved by the vehicle driver the lever may be sprung for selective engagement with the various notches of the segment I56". Thus, the segment 156 has the notches I66", I61", l68 I 89 and 110 respectively adapted, when engaged with the selector arm I53", to manipulate the transmission C? (within certain limitations and conditions which will hereinafter be more apparent) into first speed, second speed, direct drive,

neutral and reverse drive. The valve 233 is adapted for actuation by the selector lever I 53 through a Bowden wire 245 which is connected at 246 to a lever 241 which is securely fixed to the valve 233 at the axis of oscillation of the valve.

The pump H is preferably of the well known swash plate variety and is driven from its location in the oil storing reservoir I24" of a transmission casing 248 by a vertical shaft 249 having a gear driven by the gear I28" fixed to the driving sleeve 29' of the driving vane member 2|".

The shaft 249 enters the pump casing I19" to actuate the pump in a well whereby the fluid is received through the passage I 83" and discharged under pressure through the passage I84 by the reciprocating pistons I94".

The pistons I94 are contrplled by the swash plate 19!", against the upper surface of which the pistons bear as they are rotated. The swash plate is pivotally supported at 199" on the' casing 248 and the portion of the plate in contact with the pistons I 94' is illustrated in Fig. 16 as inclined with respect to the horizontal.

As the movable parts of the pump H are rotated by the shaft 243, with the plate l'9l positioned as in Fig. 16 for maximum stroke, approximately half of the pistons I94 are moving inwardly to draw in fluid in the well known manner of pumps of this type illustrated in the aforegoing embodiment, while the remaining pistons are discharging fluid under pressure for passage through the passage 184 An extension 250 of the swash plate liil is normally acted upon by a piston 25l adapted to reciprocate within a cylinder 252 of a projection 253 of the casing 248 in response to variations in fluid pressure within the cylinder. Fluid pressure is introduced into the cylinder 252 by a leadogfa conduit 254 communicating with the passage By properly positioning the piston 25l with regard to the normal distance between the swash plate support I99 and the line of action of the piston 25I, and by using the proper effective area of the piston 25l subject to the fluid pressure, the pump H will level off or become ineflective when a predetermined fluid pressure is provided in the passage 184 As the fluid pressure reaches the desired maximum determined by the piston 25!, the fluid pressure acts through the pistons |94 which are exposed to the passage I84 to cause the swash plate l9l to swing about the pivotal support I99 toward a level-off position by gradually having the stroke of the pistons 194 reduced. When fully levelled off the pistons 194 will not reciprocate until the delivery pressure falls, at which time the force of the piston 25! against the swash plate is reduced to progressively increase the inclination of the swash plate.

To automatically control the fluid pressure delivered by the pump H in response to the selection of the various speed ratio controlling devices 32 to 35 a piston 255 is adapted to bear against the swash plate extension 250, in opposition to the action of the piston 25I, to eiTect a condition in the fluid pressure system wherein the pump provides a predetermined fluid pressure to actuate the reverse speed ratio controlling device 35. We desire to point out that similar controlling means may be provided for the other speed ratio controlling devices without departing from the scope of our invention.

The piston 255 is adapted to reciprocate within known manner a cylinder 256 of an extension 251 of the casing 248 in response to fluid pr essurewithin the cylinder. Fluid pressure is introduced into the oriinder 256 by a reverse drive lead-off conduit 268 (best shown in Figs. 14 and 17) communicatin with the reverse speed ratio conduit 2 By properly positioning the piston 255 with regard to the effective distance between the lines of action of it and the piston 25I, and by using the proper effective area of the piston 255 subject to the fluid pressure, the swash plate of the pump will level of! when a predetermined fluid pressure is provided in the passage I84". This predetermined fluid pressure for actuating the reverse speed ratio controlling device 35" is preferably higher than that for actuating the other controlling devices 32" to 34" inasmuch as relatively higher torque is transmitted by the reverse gear train.

Upon selecting the reverse speed ratio drive of the transmission the valve 233 is rotated simultaneously to place the distributing outlet 231 in communication with the conduit 2. This movement of'the valve 233 admits the fluid pressure from the fluid pressure chamber 234 into the conduit 2 to actuate the controlling device 35" and simultaneously introduces the fluid pressure into the lead-off conduit 258 to force the piston 255 against the swash plate I9I". The introduction of the fluid pressure to move the piston 255 makes it necessary for the pistons I94" of the pump to provide increased fluid pressure in the passage I64" and the cylinder 252 with which to cause the piston 25I to level oil the swash plate against the opposing force of the piston 255 when the predetermined maximum fluid pressure for reverse speed has been effected. I

With reference now to the operation of the illustrated power transmitting mechanism, let it be presumed that the parts are positioned in neutral with the selector arm I53" registering with the neutral notch I 69". At this time the distributor valve outlet 231 is positioned opposite the neutral space 242 of the valve casing 232 so that the fluid pressure is not being delivered to any of the speed ratio controlling devices32" to 35" of the transmission. When the selector arm registers with the notches I66", I61", I68" or I69" the pistons I94" of the pump continue to reciprocate until the fluid pressure in the passage I84" reaches the predetermined maximum" pressure for actuation of the devices 32" to 34", at which time the piston 25I progressively levels of! the swash plate I9I".

Now let it be presumed that the vehicle operator wishes to drive the vehicle in one of its forward speeds, such as first speed for example. The selector arm I53" is moved out of engagement with the neutral notch I 63" and into the first speed notch I 66" as illustrated.

Presuming now that the vehicle operator wishes to select a higher speed ratio from the illustrated first speed condition, he moves the selector arm I53" out of engagement with the first speed notch I66" and into the second speed notch I61". The distributor valve outlet 231 isthen positioned in communication with the second speed conduit 239, it being apparent that the first speed conduit 238 is opened to the low pressure chamber 235 and the spring 225 associated with the first speed controlling device 32" will move the pistons 221 and 228 toward each other, the fluid displaced thereby returning through the inlet 23I and thence to the reservoir I24" by reason of he return conduit 243. In the meantime, the fluid pressure being supplied to the second speed con- In a similar manner the driver may then select third speed, if desired, by moving the selector arm I53" out of engagement with the second speed notch I61" and into the third speed notch I68".. 'I'hereupon the distributor valve outlet 231 is moved adjacent the third speed conduit 240, the second speed conduit 23!! being then placed in communication with the low pressure chamber 235. The fluid pressure being supplied in the meantime to the third speed conduit 240 causes the third speed controlling device 34" to be energized to produce a drive in the third speed or direct drive. It is not necessary for the vehicle operator to shift the selector arm I53" into the notches I66", I61" and I68" in this particular sequence to oper ate the vehicle in its forward speeds. In other words, he may, for example, move the selector arm I53" directly from the first speed notch I66" into the third speed notch I68".

If it is desired to drive the vehicle in reverse, the operator moves the selector lever I53" into the reverse drive notch I10" much in same manher as for the earlier described selection of the forward speeds of the transmission. The distributor valve outlet 231 is thereupon moved to communicate with the reverse speed conduit 24I and the fluid pressure is simultaneously admitted into lead-off conduit 258.

The fluid pressure thus introduced into the reverse speed conduit 24I tends to energize the reverse drive controlling device 35" to produce the reverse drive. pressure in the conduit 258 causes the piston 255 to force the swash-plate I9I" downwardly so that the pump pistons I94" must produce increased fluid pressure before the piston 25I will level off the swash-plate. This increased fluid pressure provided by the pistons I94" in response to the introduction of fluid pressure in the conduit 258 is practically instantaneous and the pump pistons continue to reciprocate to increase the fluid pressure in the pressure system until the aforesaid predetermined maximum fluid pressure for actuating the reverse drive controlling device 35" is effected. The increased fluid pressure thereby provided by the pump, after the original introduction of fluid pressure into the conduit 2, immediately further actuates the device 35" to satisfactorily I completely control the torque transmitted by the reverse gear train.

The means provided for completely controlling the reverse drive controlling device 35" is practically instantaneous in its response to the registering of the selector arm I53" with the reverse drive notch I13", and no other remote controls are necessary. e

When the vehicle operator wishes to select one of the forward speeds or neutral from the aforesaid reverse drive condition, he swings the selector arm I53" out of engagement with the reverse notch I10" and into one of the notches I66" to I69". The distributor valve outlet is simultaneously positioned in communication with one of the conduits 238 to 243, respectively. During this movement of the selector lever I53" the reverse speed conduit 243 is opened to the low pressure chamber 235 to return the displaced fluid through he reservoir return conduit 243 much in the Almost instantaneously the fluid piston 255 will no longer force the swash-plate lill downwardly. With the piston "I not being opposed by the piston 255 the pistons I 84' will continue to reciprocate only until the fluid pressure in the passage I84" is suflicient to cause the piston 25l to level ofl the swash-plate "I", at which time the fluid pressure within the pressure system is at its aforesaid predetermined maximum pressure for actuating the forward speed controlling devices 32" to 34'. This response of the pump to the reduction of pressure in the conduit 258 is practically instantaneous with this selection of one of the notches I66" to I 69".

Refen'ing now to the modified embodiment illustrated in Fig. 18, an improved swash plate pump is made possible by our pump pressure regulating means. It will be understood that this modified arrangement is intended to be substituted for the corresponding parts previously described in Figs. 14 to 17, and the entire mechanism and the operation of the same will not again be duplicated. Parts of similar function but different construction have been indicated by primed x reference characters.

The swash plate l9! is pivotally mounted at 259 near the central portion of the former. A

yielding means such as a spring 260 may be interposed between the swash plate and a spring abutment member 2! to assist in returning the swash plate from its leveled off position. During the operation of the illustrated embodiment of Fig. 18 when the selector lever I53 registers with one of the forward speed notches and the neutral space I66" to I68 and I69 respectively, at which time the piston 255 does not oppose the piston 25!, the pistons I94 of the pump H continue to reciprocate until the fluid pressure in the passage Ill is suflicient to cause the piston 25! to level ofl the swash plate. The location and rate of the spring 260, as well as the effective area of the piston 25| subjected to the fluid pressure developed by the pump, are such that when the swash plate levels 011 under these conditions the fiuid pressure within the system is the aforesaid predetermined maximum fluid pressure for actuating the selected forward speed controlling device 32'', 33 or 34".

Upon movement of the selector lever I53" to the reverse drive notch I10 the developed fluid pressure in the system also communicates with the piston 255 to cause the piston to bear against the swash plate. With the piston 255 acting against the swash plate the pump pistons I94 continue to reciprocate until sufiicient fluid pressure is produced in the system to cause the piston 2! to level off the swash plate, at which time the fluid pressure within the system is at the aforesaid predetermined maximum fluid pressure for actuating completely the reverse drive controlling device 35".

The swash plate l9l by reason of its centrally positioned pivotal support 259 effects through the pump pressure regulating means an improved control of the pump H". This swash plate will evenly control the pistons of the illustrated pump although relatively short-stroke pistons are used. It is possible with the swash plate lill to completely control the relatively short-stroke pistons I94 whereas with the type of swash plate illustrated at I3! in Fig. 17 the extended pistons must have a relatively long stroke to ride on the swash plate at all times until the swash plate is completely leveled oil.

Less efl'ort is required to level of: the swash plate l9l than the type illustrated at I!" in Fig. 17 inasmuch as in the former about half of the pump pistons are tending to balance the plate, resulting in an easily controlled pump and a cushioning of the fluid therein.

With reference now to the modified embodiment in Fig. 19, a diiferential pressure piston is illustrated as being included in our pump pressure regulating means. that this modified arrangement is intended to be substituted for the corresponding parts previous- In the operation of the'Fig. l9 embodiment the point of action of the piston 25H on the swash plate Isl, and the eilective area of the piston sealing member 263, are such that when the fluid pressure is not admitted into the reverse drive forward speed c ontrolling devices 32 to 34.

If now the selector lever I53 is registered with the reverse notch I'Hl the fluid pressure is admitted to the conduits 2M and 258 The fluid under pressure in the conduit 258 enters into the pressure chamber 266 to oppose the pressure on the piston sealing member 263 by the fluid in the pressure chamber 264 and the passage 254* communicating with the passage I84".

The point of contact of the piston 25! on the swash plate l9| and the ratio of effective areas the chamber I 94" will continue to reciprocate until suflicient fluid pressure is produced in the passages I84" and 254* to cause the piston 25! to level off the I departing from the spirit from the scope of the appended claims.

What we claim is:

1. In a motor vehicle transmission having a plurality of speed ratio controlling devices, pressure fluid operated means including a common operating member for selectively operating said devices, manually operable means for control- It will be understood 7' ling the selective operation of said operating member, means for supplying pressure fluid to said member, means including an element operable by the fluid pressure delivery of said supply means ior controlling the pressure delivery of the latter, and means operable by said member in response to selective operation of the latter by said manually operable means for varying the fluid pressure operation of said element.

2. In a motor vehicle transmission having a plurality of speed ratio controlling devices, pressure fluid operated means for selectively operating said devices, means for controlling the selective operation of said pressure fluid operated means, means for supplying pressure fluid to said pressure operated means, mechanism responsive to the fluid pressure of said supply means for controlling the pressure of fluid delivered by the latter, and means operable by said presure fluid operated means in response to selective operation of the latter for regulating the pressure responsive action of said mechanism.

3. In a motor vehicle transmission having a plurality of speed ratio controlling devices, fluid pressure operated means including a common operating member for selectively operating said devices, manually operable means for controlling the selective operation of said operating member, means responsive to operation of said manually operable means for controlling the supply of pressure fluid to said operating member, and means operable by said member in response to selective operation thereof by said manually operable means for regulating the pressure of fluid delivered by said supply means.

4. In a motor vehicle transmission having a a plurality of speed ratio controlling devices, pressure fluid operating means including a common operating member for selectively operating said devices, manually operable means for controlling the selective operation of said operating member, means for supplying pressure fluid to said member, and means operable by said member for regulating the pressure of the fluid delivered by said supply means in timed relation to the selective operation of one of said devices.

5. In a motor vehicle transmission having a plurality of speed ratio controlling devices, fluid pressure operated means for actuating said devices, manually operable means for causing selective operation of said devices, means including a pump for supplying fluid pressure for operation of said devices, a wobble plate structure for regulating the pressure of fluid deliveredby said pump, means including an element responsive to pressure of fluid delivered by said pump for controlling said wobble plate structure, and means responsive to the operation of said manually operable means for causing the fluid pressure delivered by said pump to oppose the normal control of said wobble plate structure by said pressure responsive element in response to the selective operation of one of said devices.

6. In a motor vehicle transmission having a plurality of speed ratio controlling devices, fluid pressure operated means for actuating said devices, manually operable means for causing selective operation of said devices, means including a pump for supplying fluid pressure for operation of said devices, a wobble plate structure for regulating the pressure of fluid delivered by said pump, means including a member responsive to the pressure of fluid delivered by said pump for normally controlling said wobble plate structure, and a second pressure responsive member operable in response to operation of said manually operable means for varying the control of said wobble plate structure by said first member.

7. In a power transmitting mechanism including a plurality of selectively operable fluid pressure operated speed ratio controlling devices, a pump for supplying a fluid under operating pressure for operation of said devices, fluid pressure operated means operable to vary the pressure of fluid delivered by said pump, valve means operable to effect selective application of fluid pressure to said devices, manually operable means for effecting operation of said valve means, and means responsive to operation of said manually operable means for causing said fluid pressure operated means to vary the pressure of fluid delivered by said pump.

8. In a power transmitting mechanism including a plurality of selectively operable fluid pressure operated speed ratio controlling devices, a pump for supplying a fluid under operating pressure for operation of said devices, fluid pressure operated means operable to vary the pressure of fluid delivered by said pump, valve means operable to effect distribution of pressure fluid to said devices, means operable to effect operation of said valve means, and means responsive to operation of said means to effect operation of said valve means for causing said fluid pressure operated means to vary the pressure of fluid delivered by said pump.

9. In a power transmitting mechanism including a plurality of selectively operable fluid pressure operated speed ratio controlling devices, a pump for supplying a fluid under operating pressure for operation of said devices, valve means operable to effect distribution of pressure fluid to said devices, means controlling operation of said valve means, and means operable in response to operation of said control means for varying the fluid delivery output of said pump.

10. In a power transmitting mechanism including a plurality of selectively operable fluid pressure operated speed ratio controlling devices, a pump-for supplying a fluid under operating pressure for operation of said devices, mechanism operable to vary the fluid delivery output of said pump, valve means operable to effect distribution of pressure fluid to said devices, means controlling operation of said valve means, and means operable in response to operation of said control means for causing said mechanism to vary the fluid delivery output of said pump.

11. In a motor vehicle power transmitting mechanism including a plurality of selectively operable fluid pressure operated speed ratio controlling devices, a pump for supplying a fluid under operating pressure for operation of said devices, valve means operable to effectdistribution of pressure fluid to said devices, vehicle driver operated means operable to effect operation of said valve means, and means responsive to operation of said vehicle driver means for regulating the operation of said pump.

12. In a power transmitting mechanism including a plurality of selectively operable fluid pressure operated speed ratio controlling devices, means operable to control the selective operation of said devices, a pump for supplying a fluid under operating pressure for operation of said devices, a swingably mounted member for varying the fluid delivery output of said pump, a fluid pressure actuated element acting on said member for urging the latter in one direction of its swinging movement, a second fluid pressure actuated for controlling least one of said elements a 13. In a power transmitting mechanism including a plurality of selectively operable fluid pressure operated speed ratio controlling devices,

reverse drive device.

15. In a motor vehicle operation at relatively difiering predetermined pressures of fluid,

HERBERT F. PATTERSON. AUGUsTm J. SYROVY. 

